Liberty Reserve's main line of business was operating a shared ledger trusted by multiple companies which would exchange cash for ledger entries and ledger entries for cash, earning a fee each time. Think like Western Union except minus all the pesky regulated bits. LR was a direct reaction to what had befallen e-gold, which was in fundamentally the same business except it did all of the cashing first-party (early in…
Bitcoin and other online exchange / transaction systems (e-gold, LR, etc) represent a small fraction of global money laundering, a small enough fraction to be laughable and irrelevant.
One would assume there were more than $250M in bitcoins circulating, which seems to be the threshold for prosecution here.